Air travel is popular in the poor Himalayan country, but its mountainous terrain, poor regulation and a lack of investment in planes and infrastructure have led to large numbers of accidents over the years.

Here are five things to know about flying in Nepal:

Poor national record

There have been 27 fatal plane crashes in Nepal in the past three decades — an average of almost one per year, according to the independent Aviation Safety Network database.

More than 20 of these occurred in the last decade alone and seven killed 18 people or more.

All its airlines are barred from flying in European Union airspace.

The majority of crashes happened at small domestic airports where pilots negotiated small planes onto tiny strips of tarmac — in some cases hewn into steep mountainsides.

But the worst have occurred at Kathmandu’s single-runway airport, which services both international and domestic routes.

In 1992, two planes crashed near Kathmandu within just two months of one another, killing a total of 280 people.

Although most of the biggest accidents have occurred in Kathmandu, most pilots acknowledge that the precipitous landing strips high in the Himalayas are the toughest to negotiate.

Lukla — the gateway to Mount Everest — has been dubbed the world’s most dangerous airport, requiring the pilot to navigate through narrow mountain gorges before landing on a steep runway just 500 metres (yards) long with precipitous drops on either side.

In 2008, a passenger plane crashed on landing at Lukla, killing everyone on board except the pilot.

“The country’s beautiful but rugged terrain makes the safety of air operations more challenging than in other areas of the world,” says the International Civil Aviation Organization, a UN special agency.